We have to remember that in one-to-one functions each element of the domain maps to a different element in the range.
When we have a bijection we have that each element in the set A, for example, corresponds to exactly one element of B, and vice versa.
When we have a bijection, we also have an inverse function.
Then, we have that:

To find the inverse, we have to interchange the variables:

Now, we have:

And we need to solve for y:
1. Add 13 to both sides of the equation:

2. Divide both sides by -2:

Then, we have that:

We can check this if we make a composition between the two functions (then we will get x as a result).

Then, we have that the result for this composition is equal to x. Thus:

We also have that:
We have that h(4) = 3, then h^(-1)(3) = 4 or

In summary, we have:


